Vertical distribution of alewife in the Lake Ontario offshore: Implications for resource use

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F17%3A00480484" target="_blank" >RIV/60077344:_____/17:00480484 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.jglr.2017.07.007" target="_blank" >http://dx.doi.org/10.1016/j.jglr.2017.07.007</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jglr.2017.07.007" target="_blank" >10.1016/j.jglr.2017.07.007</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Vertical distribution of alewife in the Lake Ontario offshore: Implications for resource use

Popis výsledku v původním jazyce

Oligotrophication of Lake Ontario has led to increased water clarity and an increased proportion of zooplankton residing in the metalimnion during the day, which may affect the utilization of different depth regions for planktivorous fish. We investigated day and night distributions of fish using hydroacoustics and suspended vertical gillnets during the summer of 2013 when a deep chlorophyll layer (DCL) was established. We related fish distributions to concurrent measures of temperature and prey (zooplankton) density. Alewife dominated in vertical gill net catches, indicating that most acoustic targets were alewife. Alewife schooled during the day in the bottom of the mixed layer, and at dusk alewife schools broke up and fish moved towards the surface. We hypothesize this movement followed migrating zooplankton to allow feeding at night, alewife sampled from vertical gillnets fed on cyclopoid copepods and cladocerans, prey groups that migrate into the epilimnion at night. Some alewife remained at the bottom of the mixed layer at night and these fish ate deep-water calanoid copepods such as Limnocalanus. Vertical distributions were best predicted by temperature and the interaction between temperature and zooplankton density. We include uplooking acoustics data to complement our downlooking datasets, which provided evidence for potential bias in downlooking acoustic assessments of alewife due to high proportions of alewife found in the surface exclusion zone. Our approach combining several datasets provides a new perspective to understand summer diel distribution of alewife and the factors driving their distribution.

Název v anglickém jazyce

Vertical distribution of alewife in the Lake Ontario offshore: Implications for resource use

Popis výsledku anglicky

Oligotrophication of Lake Ontario has led to increased water clarity and an increased proportion of zooplankton residing in the metalimnion during the day, which may affect the utilization of different depth regions for planktivorous fish. We investigated day and night distributions of fish using hydroacoustics and suspended vertical gillnets during the summer of 2013 when a deep chlorophyll layer (DCL) was established. We related fish distributions to concurrent measures of temperature and prey (zooplankton) density. Alewife dominated in vertical gill net catches, indicating that most acoustic targets were alewife. Alewife schooled during the day in the bottom of the mixed layer, and at dusk alewife schools broke up and fish moved towards the surface. We hypothesize this movement followed migrating zooplankton to allow feeding at night, alewife sampled from vertical gillnets fed on cyclopoid copepods and cladocerans, prey groups that migrate into the epilimnion at night. Some alewife remained at the bottom of the mixed layer at night and these fish ate deep-water calanoid copepods such as Limnocalanus. Vertical distributions were best predicted by temperature and the interaction between temperature and zooplankton density. We include uplooking acoustics data to complement our downlooking datasets, which provided evidence for potential bias in downlooking acoustic assessments of alewife due to high proportions of alewife found in the surface exclusion zone. Our approach combining several datasets provides a new perspective to understand summer diel distribution of alewife and the factors driving their distribution.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10617 - Marine biology, freshwater biology, limnology

Projekt

<a href="/cs/project/LD15021" target="_blank" >LD15021: Co zde pohledáváš? Distribuce a aktivita ryb ve velkých stojatých vodách</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Great Lakes Research

ISSN

0380-1330

e-ISSN

—

Svazek periodika

43

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

823-837

Kód UT WoS článku

000411533900006

EID výsledku v databázi Scopus

2-s2.0-85027156718